Flow sim can calculate the loads and enable those loads for use by SWX Sim which can compute the structural response (stresses). You would need both to do precisely what you stated. However, you can probably do a very decent job by a hand calc on the loads and calculate the stresses with SWX Sim.
You could calculate the loads reasonably accurately, assuming your fluid mixture is cohesive. However the CFD-FEA couping is one way and not time dependent. This means you would get the fluid pressures at a single point in time and use that to calculate the resultant mechanical stress.
Buen dia, trabaje en una empresa en donde fabrican tanques con agitadores y al igual que usted estuve interesado en el análisis con CFD, le recomendaría para este tipo de análisis el uso de ANSYS.